Groin injury risk of pubertal soccer players increases during peak height velocity due to changes in movement techniques.

Adolescent athletes experience an increase in injury incidence when they undergo peak height velocity (PHV). To find the reason behind this increase, the present study investigated if PHV influences hip joint kinematics, kinetics and adductor muscle forces in two groups of adolescent soccer players performing 90°-cutting manoeuvres and inside passing. One group was estimated to be more than half a year before PHV (PRE, N = 12). The second group was estimated to be less than half a year before or after PHV (MID, N = 10). Maximum static gripping and adductor forces were measured. Motion capturing and inverse dynamics were used to calculate kinematics and kinetics. The MID group was significantly taller and heavier compared to PRE while the force measurements showed no differences. Statistics showed a higher hip abduction moment for MID during the cutting manoeuvre. Results from the anthropometrics and force measurements suggest that the moments of inertia of the participants' extremities increase faster than the muscles can adapt. A higher abduction moment of MID likely increases the load on the adductor muscles through a change of technique. Combining both findings, it is likely that the risk of suffering a groin injury is increased in the MID group.